Creating the correct payload for a transaction is non-trivial, as it requires cryptographic functions and a specific serialization protocol. Our crypto SDKs provide the functionality needed in most major programming languages.

Unconfirmed transactions have not been incorporated in the blockchain, but reside in the mempool. Although usually the mempool is cleared within minutes, during high network load a transaction with a low fee will live here for a considerable time. If you have set the transaction with a fee of near zero, it might not be picked up by a Delegate and will time out.

For fine-grained searches, use the search endpoint. Note that unless you use specific body parameters, the response might contain a large number of transactions (hundreds of thousands). It is best to filter as many transactions node side, instead of dissecting the response client side.